From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 1 May 2025 23:59:30 +0000 (-0400)
Subject: attach_recursive_mnt(): remove from expiry list on move
X-Git-Tag: block-6.17-20250808~63^2~25
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a8c764e1a580c2128e905ad6e42beef413fb7177;p=linux-block.git

attach_recursive_mnt(): remove from expiry list on move

... rather than doing that in do_move_mount().  That's the main
obstacle to moving the protection of ->mnt_expire from namespace_sem
to mount_lock (spinlock-only), which would simplify several failure
exits.

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/namespace.c b/fs/namespace.c
index 7c7cc14da1ee..e8dc8af87548 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2684,6 +2684,9 @@ static int attach_recursive_mnt(struct mount *source_mnt,
 	if (moving) {
 		umount_mnt(source_mnt);
 		mnt_notify_add(source_mnt);
+		/* if the mount is moved, it should no longer be expired
+		 * automatically */
+		list_del_init(&source_mnt->mnt_expire);
 	} else {
 		if (source_mnt->mnt_ns) {
 			LIST_HEAD(head);
@@ -3674,12 +3677,6 @@ static int do_move_mount(struct path *old_path,
 		goto out;
 
 	err = attach_recursive_mnt(old, p, mp);
-	if (err)
-		goto out;
-
-	/* if the mount is moved, it should no longer be expire
-	 * automatically */
-	list_del_init(&old->mnt_expire);
 out:
 	unlock_mount(mp);
 	if (!err) {